KR-102962532-B1 - ELECTRODE FOR SECONDARY BATTERY AND MANUFACTURING METHOD FOR THE SAME

KR102962532B1KR 102962532 B1KR102962532 B1KR 102962532B1KR-102962532-B1

Abstract

The present invention relates to an electrode for a secondary battery and a method for manufacturing the same, wherein a separate conductive material and a polymer binder can be omitted by coating a metal particle with high electrical conductivity and a particle with high ion conductivity onto an electrode active material. A method for manufacturing an electrode for a secondary battery according to one embodiment of the present invention is a method for manufacturing an electrode for a secondary battery, comprising the steps of: preparing an electrode active material having a first coating particle having electrical conductivity and a second coating particle having ion conductivity coated on its surface; preparing an electrode by placing the prepared electrode active material on an electrode substrate and molding it; and densifying the prepared electrode by compressing it under high pressure. After the above densification step, the process further includes a step of sintering the densified electrode active material.

Inventors

김용상

Dates

Publication Date: 20260507
Application Date: 20230310

Claims (20)

A method for manufacturing an electrode for a secondary battery, A step of preparing an electrode active material having a first coating particle having electrical conductivity and a second coating particle having ion conductivity coated on its surface; A step of preparing an electrode by placing a prepared electrode active material on an electrode substrate and molding it; and It includes a step of densifying the prepared electrode by compressing it, A method for manufacturing an electrode for a secondary battery, characterized in that the first coating particle is one or more selected from tin, silver, copper, antimony, lead, or Sn-Ag-Cu solder alloy (SAC), and the second coating particle is one or more selected from aluminum oxide, silver oxide, or copper oxide.
In claim 1, After the aforementioned densification step, A method for manufacturing an electrode for a secondary battery, further comprising the step of sintering the electrode active material that has undergone densification.
In claim 1, The step of preparing the above electrode active material is, A process of preparing a first coating particle having electrical conductivity and a second coating particle having ion conductivity; A process of preparing a coating particle dispersion by adding the prepared first coating particles and second coating particles to a solvent and dispersing them; A process of immersing an electrode active material in a prepared coating particle dispersion and mixing it to coat the surface of the electrode active material with a first coating particle and a second coating particle; A process of drying an electrode active material coated with first coating particles and second coating particles; and A method for manufacturing an electrode for a secondary battery, comprising the process of grinding a dried electrode active material.
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In claim 1, A method for manufacturing an electrode for a secondary battery, characterized in that the melting point of the second coating particle is higher than the melting point of the first coating particle.
In claim 3, In the process of preparing the above coating particle dispersion A method for manufacturing an electrode for a secondary battery, characterized in that the first coating particles and the second coating particles are mixed in a volume ratio of 1 to 5:1.
In claim 3, In the process of coating the surface of the above electrode active material with the first coating particles and the second coating particles, A method for manufacturing an electrode for a secondary battery, characterized in that the above electrode active material is mixed in an amount of 60 to 98 wt% and the coating particles are mixed in an amount of 2 to 40 wt%, wherein the coating particles are a mixture of the first coating particles and the second coating particles.
In claim 3, In the process of drying the above electrode active material, A method for manufacturing an electrode for a secondary battery, characterized in that the drying temperature is 90 to 100℃.
In claim 2, In the above sintering step, A method for manufacturing an electrode for a secondary battery, characterized by performing sintering at 200 to 1000℃ for 5 to 10 minutes.
In claim 2, In the step of preparing the above electrode, The above electrode active material is mixed with a predetermined polymer binder and placed on an electrode substrate, and In the above sintering step, A method for manufacturing an electrode for a secondary battery, characterized in that a predetermined polymer binder included in the electrode is removed.
Electrode substrate and; The electrode active material portion is formed by mutually bonding an electrode active material having a first coating particle having electrical conductivity and a second coating particle having ion conductivity coated on the surface of the electrode substrate. An electrode for a secondary battery, characterized in that the first coating particle is one or more selected from tin, silver, copper, antimony, lead, or Sn-Ag-Cu solder alloy (SAC), and the second coating particle is one or more selected from aluminum oxide, silver oxide, or copper oxide.
In claim 11, An electrode for a secondary battery characterized in that the above electrode active material portion does not contain a polymer binder.
In claim 11, The above electrode active material part is, A plurality of electrode active materials and; An electrode for a secondary battery comprising a coating layer on the surface of the above electrode active material, wherein the first coating particle and the second coating particle are coated.
In claim 13, An electrode for a secondary battery, characterized in that the coating layer is coated with the first coating particles sintered to a predetermined thickness on the surface of an electrode active material, and the second coating particles are dispersed and distributed among the sintered first coating particles.
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In claim 11, An electrode for a secondary battery characterized in that the melting point of the second coating particle is higher than the melting point of the first coating particle.
In claim 13, The electrode for a secondary battery is characterized in that the above electrode active material portion is formed by bonding coating layers coated on the surface of the electrode active material to each other.
In claim 17, An electrode for a secondary battery, characterized in that the bonding between the above coating layers is achieved by the first coating particles forming the coating layer being bonded to each other and becoming integrated through sintering treatment of the first coating particles.
It comprises an electrode substrate; and an electrode active material portion formed by mutually bonding an electrode active material having a first coating particle having electrical conductivity and a second coating particle having ion conductivity coated on the surface of the electrode substrate. A secondary battery comprising an electrode as a negative electrode, characterized in that the first coating particle is one or more selected from tin, silver, copper, antimony, lead, or Sn-Ag-Cu solder alloy (SAC), and the second coating particle is one or more selected from aluminum oxide, silver oxide, or copper oxide.
In claim 19, It further includes an anode and an electrolyte, A secondary battery characterized in that the above electrolyte is a solid-state electrolyte.

Description

Electrode for secondary battery and manufacturing method for the same The present invention relates to an electrode for a secondary battery and a method for manufacturing the same, and more specifically, to an electrode for a secondary battery and a method for manufacturing the same in which a separate conductive material and a polymer binder can be omitted by coating a metal particle with high electrical conductivity and a particle with high ion conductivity onto an electrode active material. Rechargeable batteries are used as high-capacity power storage batteries for electric vehicles and battery power storage systems, as well as as small, high-performance energy sources for portable electronic devices such as mobile phones, camcorders, and laptops. Along with research on component lightweighting and low power consumption aimed at miniaturizing portable electronic devices and enabling long-term continuous use, there is a demand for rechargeable batteries that are compact yet capable of realizing high capacity. In particular, lithium-ion batteries, a representative type of rechargeable battery, have a higher energy density, greater capacity per unit area, a lower self-discharge rate, and a longer lifespan than nickel-manganese or nickel-cadmium batteries. Additionally, they lack a memory effect, offering convenience of use and long lifespan characteristics. In a lithium secondary battery, electrical energy is produced by oxidation and reduction reactions when lithium ions are inserted into or removed from the positive and negative electrodes, while the electrolyte is charged between the positive and negative electrodes, which are composed of active materials capable of lithium ion intercalation and deintercalation. These lithium secondary batteries consist of components such as a positive electrode, an electrolyte, a separator, and a negative electrode. In this case, the positive electrode is composed of lithium oxide (Li+O) formed by the combination of lithium and oxygen. During charging, lithium ions are deintercalated from the active material constituting the positive electrode and move to the negative electrode to charge it, while during discharging, lithium ions move from the negative electrode to the positive electrode to generate electricity. The positive electrode primarily determines the battery's capacity and voltage, while the negative electrode primarily determines the charging speed. In order to increase the charge capacity of a lithium secondary battery, a large amount of lithium must be included in the cathode, but increasing the amount of lithium not only increases costs but also has technical limitations. Graphite, widely used as an active cathode material, has the advantages of being inexpensive and having a stable crystal structure, but it has the drawback of requiring a long charging time. To solve this problem, a certain amount of silicon-based material is incorporated into the graphite; however, silicon undergoes volume expansion (swelling) during repeated charging and discharging cycles, which can lead to battery explosions. To address this volume expansion problem, research on using graphene composites with silicon has recently been actively underway. Graphene is a two-dimensional nanomaterial composed of hexagonal carbon atoms that exhibits excellent electrical conductivity, electrochemical stability, and a mesh structure with superior mechanical strength. It is known to mitigate the volume expansion issues and the resulting structural fragmentation of silicon. However, from a commercialization perspective, the development of silicon/graphene composites capable of maintaining price competitiveness remains a distant prospect. The content described above as background technology is intended only to help understand the background of the present invention and should not be construed as an acknowledgment that it constitutes prior art already known to those skilled in the art. FIG. 1 is a schematic diagram showing a secondary battery with an electrode applied according to one embodiment of the present invention, and FIG. 2 is a schematic diagram showing the electrode after sintering according to one embodiment of the present invention, and Figures 3a and 3b are graphs showing the results of evaluating the cycle stability characteristics of the example and the comparative example. Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are given the same reference number, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably solely for the ease of drafting the specification, and do not inherently possess distinct meanings or roles. In describing the embodiments disclosed in this specification, if it is determined that a detailed description of